First-level removable module having bar code I/O and second-level removable memory

ABSTRACT

Methods and apparatus for closed-case removable expansion cards having a removable memory enhance the utility of portable computer hosts, such as PDAs. In both a first and second embodiments the closed-case removable expansion cards preferably use a Type II CompactFlash form factor. In the first embodiment the removable memory is in combination with an external-I/O connector or attached external-I/O device, providing both I/O and memory functions in a single closed-case removable expansion card. This increases the expansion functional density for portable computer hosts, such as PDAs. That is, it increases the amount of functionality that can be accommodated within a given volume allocation for expansion devices. In the second embodiment the removable memory is a private memory for application specific circuitry within the closed-case-removable expansion card. This enhances the utility of portable computer hosts, such as PDAs, as universal chassises for application specific uses. The standard CompactFlash physical and electrical interface couples the application specific card to the host, which provides user interface functions for the application. The cards include a top located slot and an internal connector for accepting a MultiMediaCard as the private removable memory. In addition, the application specific card will generally have some manner of I/O to required external devices, such as scanning devices, sensors, or transducers. Otherwise, all functionality for the application specific function is self-contained within the application specific card.

FIELD

[0001] The invention is related to closed-case removable expansion cardsfor computer hosts, such cards having particular application to portablecomputer hosts such as handheld computing devices.

BACKGROUND

[0002] The broad use of portable host computers, including PersonalDigital Assistants (PDAs), has been severely hampered by limitedcapabilities for expansion or customization. Expansion and applicationcustomization has been performed via only one, or at most two, slots forremovable expansion cards for I/O, I/O adapters, memories, and memoryadapters. Memory expansion cards have included DRAM, SRAM, ROM, andFlash technologies. I/O expansion cards have included dedicatedperipherals, networking, modems, wireless communications, serial I/O,and bar-code and other scanners.

[0003] Having only one slot meant choosing between memory or peripheralexpansion. In two-slot implementations, one of the slots is generallyused for peripheral expansion, and the other for memory expansion. Asmarket forces and consumer demand are pushing future PDAs to be eversmaller, allocating packaging volume for two-slots will be increasinglyviewed as a costly and nonviable solution.

[0004] Memory and Expansion Card Standards

[0005] Two of the most popular industry standards for the slots andremovable cards are the PC Card and the CompactFlash Card. The PC Cardhas a 16-bit variant, previously known as a PCMCIA card, and a newer32-bit variant, also known as a Card-Bus card. U.S. Pat. No. 5,815,426('426), ADAPTER FOR INTERFACING AN INSERTABLE/REMOVABLE DIGITAL MEMORYAPPARATUS TO A HOST DATA PART, assigned to Nexcom Technology, and herebyincorporated by reference, describes these and other removable expansioncard and memory types suitable for PDAs. In addition to the PC Card andCompactFlash Card formats, the '426 patent includes discussions of andreferences to Miniature Cards, Sold State Floppy Disk Cards (SSFDCs),MultiMediaCards (MMC), Integrated Circuit (IC) Cards (also known asSmart Cards), and Subscriber Identification Module (SIM) Cards.

[0006] CompactFlash Card

[0007]FIGS. 1A, 1B, and 1C are different views of a prior art Type IICompactFlash Card. The CompactFlash physical, electrical, and softwareinterface architecture is taught in the CompactFlash SpecificationRevision 1.3, Copyright 1998, by the CompactFlash Association, P.O. Box51537, Palo Alto, Calif. 94303, which is hereby incorporated byreference. FIGS. 1A, 1B, 1C, part of 6A, and part of 6B are reproducedor derived from the CompactFlash Specification document.

[0008] U.S. Pat. No. 5,887,145 ('145), REMOVABLE MOTHER/DAUGHTERPERIPHERAL CARD, assigned to SanDisk Corporation, and herebyincorporated by reference, describes the required features of hostsystems for CompactFlash Cards, including controllers required byCompactFlash memory cards (CF cards) and comprehensive controllersrequired by CompactFlash memory and I/O cards (CF+cards).

[0009] MultiMediaCard

[0010]FIGS. 2A and 2B represent a prior art MultiMediaCard form factorand its pad definitions. FIGS. 3A and 3B represent the prior artinternal architecture of a generic MultiMediaCard and its registers.FIG. 4A illustrates the prior art functional partitioning of a genericMultiMediaCard system. FIG. 5 illustrates the prior art physicalpartitioning of a generic MultiMediaCard system. The MMC and MMC relatedsystem issues are taught in the MultimediaCard System Summary Version2.0, Copyright January 1999, by the MultiMediaCard Association, 19672Stevens Creek Blvd., #404, Cupertino, Calif. 95014-2465, which is herebyincorporated by reference. FIGS. 2A, 2B, 3A, 3B, 4, 5, and part of 6Aare reproduced or derived from the MultimediaCard System Summarydocument.

[0011]FIGS. 6A and 6B are different views comparing the form factors ofthe prior art CompactFlash Card (top) and MultiMediaCard (bottom). Ineach of 6A and 6B, the CompactFlash Card and the MultiMediaCard are bothroughly to equal scale.

[0012] Adapters for Removable Memories

[0013] Adapters exist or have been prophetically disclosed forphysically and electrically coupling a removable memory on a slide, orstick, to a portable host via a removable expansion card of either thePCMCIA Card or CompactFlash Card form factors. The previously mentioned'426 patent describes such removable memory adapters. The focus of theseexisting memory adapters has been limited to merely providing aninterface adapter, or bridge, between a first interface type (the hostto removable-expansion-card interface) and a second interface type (theremovable memory stick).

[0014] PC Card Mother and CompactFlash Card Daughter Combinations

[0015] Adapters exist or have been prophetically disclosed that comprisea special mother PC Card designed to accept one or more daughterCompactFlash Cards of one or more types. The previously '145 patentdescribes such CompactFlash adapters. The focus of these existingmother/daughter combinations has also been limited. First, the daughtershave been used for memory expansion for the host platform, primarily inthe form of flash-memory-based mass-storage-like devices. In this firstapproach, the mother card provides the requisite mass-storage controllerfunctionality. Second, the daughters have been used for dedicatedperipheral, I/O, or communication functions. In this second approach,the mother card has a so-called comprehensive controller that augmentsthe mass-storage controller functionality with functions commonlyrequired or useful to multiple daughter cards. Third, in a variation ofeither of the first two paradigms, functions of the general-purpose hostmay be relocated to the mother card.

[0016] Background for PC-Card Based I/O Functions

[0017] Techniques are known in the art for making and using systems thatperform such I/O functions in a PC card. For example, see U.S. Pat. No.5,671,374 ('374), PCMCIA INTERFACE CARD COUPLING INPUT DEVICES SUCH ASBARCODE SCANNING ENGINES TO PERSONAL DIGITAL ASSISTANTS AND PALMTOPCOMPUTERS, assigned to TPS Electronics, which is hereby incorporated byreference. The '374 patent teaches the use of PDAs and similar hostsequipped with PC card interfaces for I/O devices including portablelaser-scanners, magnetic stripe and ink readers, keyboards and keypads,OCR devices, and trackballs.

[0018] Techniques are also known in the art for making and using PCCard-based radios for applications based in a portable host. Forexample, see U.S. Pat. No. 5,519,577 ('577), SPREAD SPECTRUM RADIOINCORPORATED IN A PCMCIA TYPE II CARD HOLDER, assigned to SymbolTechnologies, and hereby incorporated by reference.

[0019] Techniques are also known in the art for making and using diskemulation devices based on flash memory. For example, see U.S. Pat. No.5,291,584 ('584), METHODS AND APPARATUS FOR HARD DISK EMULATION,assigned to Nexcom Technology, and hereby incorporated by reference.

[0020] Background for Relevant Application Specific Functions

[0021] Techniques are known in the art for making and using systems thatdownload or capture compressed digital audio for storage and laterplayback using dedicated removable media. For example, U.S. Pat. No.5,676,734 ('734), SYSTEM FOR TRANSMITTING DESIRED DIGITAL VIDEO OR AUDIOSIGNALS, assigned to Parsec Sight/Sound, and hereby incorporated byreference, teaches a system for transmitting digital video or audiosignals over a telecommunications link from a first to a second party.In addition, U.S. Pat. No. 5,579,430 ('430), DIGITAL ENCODING PROCESS,assigned to Fraunhofer Gesellschaft zur Foerderung der angewandtenForschung e.V., and hereby incorporated by reference, teaches processesfor encoding digitized analog signals. Such processes are useful forinsuring high-quality reproduction while reducing transmission bandwidthand data storage requirements.

[0022] Techniques are also known in the art for making and using recordand playback portable host devices based on a dedicated flash memory.For example, see U.S. Pat. No. 5,491,774 ('774), HANDHELD RECORD ANDPLAYBACK DEVICE WITH FLASH MEMORY, assigned to Comp General Corporation,and hereby incorporated by reference, and U.S. Pat. No. 5,839,108('108), FLASH MEMORY FILE SYSTEM IN A HANDHELD RECORD AND PLAYBACKDEVICE, assigned to Norris Communications, also hereby incorporated byreference.

[0023] Limitations of Previous Approaches

[0024] In general purpose portable hosts, populating an expansion slothas meant choosing one of either removable memory or peripheralexpansion for that slot. When used for memory expansion, the removablememory has been limited to use for the system or application softwarerunning on the host. In essence, the removable memory has only been usedas host-dedicated memory. This was done either directly, e.g., as someportion of the main-memory of the host, or indirectly as an emulationsubstitute for host mass-storage (i.e., disk drives).

[0025] When used for I/O expansion, the expansion I/O-cards have not hadaccess to a private removable media/memory. This has prevented portablecomputer hosts, such as PDAs, from being used as a customizable platformfor many application-specific functions that require a removable memorydedicated to the application.

SUMMARY

[0026] The utility of portable computer hosts, such as PDAs, is enhancedby methods and apparatus for closed-case removable expansion cardshaving a removable memory in both a first and second embodiment. In boththe first and second embodiments the closed-case removable expansioncards preferably use a Type II CompactFlash form factor. In the firstembodiment the removable memory is in combination with an external-I/Oconnector or permanently attached external-I/O device, providing bothI/O and memory functions in a single closed-case removable expansioncard. This increases the expansion functional density for portablecomputer hosts, such as PDAs. That is, it increases the amount offunctionality that can be accommodated within a given volume allocationfor expansion devices. It also provides a viable alternative to 2-slotimplementations. In the second embodiment the removable memory is aprivate memory for application specific circuitry within theclosed-case-removable expansion card. This enhances the utility ofportable computer hosts, such as PDAs, as universal chassises forapplication specific uses. The standard CompactFlash physical andelectrical interface couples the application specific card to the host,which provides user interface functions for the application. The cardsinclude a top located slot and an internal connector for accepting aMultiMediaCard as the private removable memory. In addition, theapplication specific card will generally have some manner of I/O torequired external devices, such as scanning devices, sensors, ortransducers. Otherwise, all functionality for the application specificfunction is self-contained within the application specific card.Particular application specific cards for customizing general purposePDAs via the instant invention include a media-player card for digitizedmedia stored on removable memory and a bar-code-scanner card havingscanning data stored on removable memory.

BRIEF DESCRIPTION OF DRAWINGS

[0027]FIGS. 1A, 1B, and 1C are different views of a prior art Type IICompactFlash card.

[0028]FIGS. 2A and 2B represent a prior art MultiMediaCard form factorand its pad definitions.

[0029]FIGS. 3A and 3B represent the prior art internal architecture of ageneric MultiMediaCard and its registers.

[0030]FIG. 4A illustrates the prior art functional partitioning of ageneric MultiMediaCard system.

[0031]FIG. 5 illustrates the prior art physical partitioning of ageneric MultiMediaCard system.

[0032]FIGS. 6A and 6B compares the form factors of the prior artCompactFlash card (top) and MultiMediaCard (bottom).

[0033]FIG. 7 illustrates a PDA equipped with a removable expansion cardhaving both I/O and removable memory in accordance with the presentinvention.

[0034]FIG. 8 illustrates some of the various types of I/O for which thePDA and removable expansion card of FIG. 7 may be equipped.

[0035]FIG. 9 is an abstract drawing representing the removable expansioncard of FIG. 7 separate from the PDA, and with the I/O and memorydisengaged from the removable expansion card.

[0036]FIG. 10 is an abstract drawing representing the constructiondetail of the upper and lower frame of the removable expansion card ofFIG. 7.

[0037]FIG. 11 is an abstract drawing representing an exploded view ofthe removable expansion card of FIG. 7, including the outer frame, innerPCB, and connectors.

[0038]FIG. 12A is an abstract drawing representing a view of theremovable expansion card of FIG. 7, with the outer frame removed, and aremovable memory roughly aligned with the contact fingers to which itmates within the removable expansion card.

[0039]FIG. 12B is an abstract drawing representing a cut away side viewof the removable expansion card of FIG. 7, with the removable memoryinserted into the removable expansion card.

[0040]FIG. 13A is an abstract drawing representing an end viewsilhouette of the removable expansion card of FIG. 7.

[0041]FIG. 13B is an abstract drawing representing a cross-sectionalview silhouette of the upper frame member of the removable expansioncard of FIG. 7.

DETAILED DESCRIPTION

[0042] Components of the Expansion Card

[0043]FIG. 9 is an abstract drawing representing a closed-case removableexpansion card 100, i.e., an expansion card that may be inserted intoand removed out of a closed-case computer host. The card is especiallysuitable for use in a portable host, such as a PDA. In accordance withthe present invention, the expansion card of FIG. 9 includes a connector141 for I/O interconnect and a slot 121 for a removable memory. FIG. 9shows the I/O interconnect 140 and removable memory 120 disengaged fromthe removable expansion card.

[0044]FIG. 10 is an abstract drawing representing the constructiondetail of the upper 105 and lower 110 frame members of the removableexpansion card 100 of FIG. 9. An opening 111 is provided in the lowerframe 110 for receiving the connector 141 for I/O interconnect.

[0045]FIG. 11 is an abstract drawing representing an exploded view ofthe removable expansion card 100 of FIG. 9, including the outer frame,inner PCB 115, and connectors. Visible for the first time in the view ofFIG. 11, a second opening 113 is provided in the lower frame 110 forreceiving the connector 150 for host interconnect. Additionally, a slot112 is provided on both sides of the opening 111 to aid in the alignmentand retention of the connector 141, and a slot 114 is provided on bothsides of opening 113 to aid in the alignment and retention of theconnector 150. An opening 116 is provided in the PCB for receiving theconnector 141.

[0046]FIG. 12A is an abstract drawing representing a view of theremovable expansion card 100 of FIG. 9, with the outer frame membersremoved, and a removable memory 120 roughly aligned with the contactfingers 180 to which it mates within the removable expansion card.Circuitry 160 is provided, including I/O adapter circuitry, removablememory adapter circuitry, and application-specific circuitry. A supportshelf 170 supports, aligns, separates, and isolates the underside of thecontact fingers 180 from the circuitry 160.

[0047]FIG. 12B is an abstract drawing representing a cut away side viewof the removable expansion card 100 of FIG. 9, with the removable memory120 inserted into the removable expansion card.

[0048]FIG. 13A is an abstract drawing representing an end viewsilhouette of the removable expansion card 100 of FIG. 9. FIG. 13B is anabstract drawing representing a cross-sectional view silhouette of theupper frame member 105 of the removable expansion card 100 of FIG. 9.Guides 190 provide alignment and support for removable memory insertedvia slot 121.

[0049] In a preferred embodiment, the expansion card 100 and associatedhost connector 150 are compatible with the Type II CompactFlash Card asdescribed in the previously referenced CompactFlash Specification. TheI/O connector 141 is compatible with a PC-Card industry standardHonda-style 15-pin connector. The slot 121, removable memory 120, andremovable memory adapter circuitry of circuitry 160, are compatible withthe MultiMediaCard as described in the previously referencedMultiMediaCard System Summary.

[0050] Circuitry on the Expansion Card

[0051] In a first embodiment of the invention, circuitry 160 includesI/O adapter circuitry and removable memory adapter circuitry. The I/Oadapter functionality may include one or more of, but is not limited to,Ethernet, serial port, audio, telephone, antenna, and special-functioninterfaces such as bar code and other scanners. The removable memoryadapter functionality may include one or more of, but is not limited to,main memory expansion, mass-media emulation, and other host-basedspecial-purpose memory applications.

[0052] In accordance with a second embodiment, circuitry 160 furtherincludes application-specific circuitry for which the management of theremovable memory is an ancillary function to the primary function of thespecific application. Specific examples of such application-specificexpansion cards having both I/O and removable memory are provided inlater sections.

[0053] In preferred implementations of both of the first and secondembodiments mentioned above, the functions performed by the removablememory are those of a MultiMediaCard adapter as illustrated in theMultiMediaCard adapter section of the MultiMediaCard system architecturediagram of FIG. 4. If the removable memory is being used to providehost-base memory expansion, such as described for the first embodiment,then the host must provide the functionality illustrated by theApplication and Application Adapter sections of FIG. 4. If the removablememory is being used at least sometimes as an ancillary memory (at leastsometimes private) to the application-specific circuitry contained onthe expansion card, such as for the second embodiment, then theapplication-specific circuitry must provide the Application andApplication Adapter section functionality, or else theapplication-specific circuitry must call on host services for suchfunctionality.

[0054] Examples of known techniques for making and using other types ofmemory adapter circuitry for closed-case expansion cards or with flashmemory are found in the previously referenced '145, '426, '584, '774,and '108 patents, among others. Examples of known techniques for makingand using I/O adapter and application-specific circuitry for functionsimplemented in closed-case expansion cards and with flash memory arefound in the previously referenced '374, '577, '774, and '108 patents,among others.

[0055] Frame Kit Assembly

[0056] The top and bottom frames may be composed of metal or plastic. Ina preferred embodiment, the top and bottom frame portions each have aplastic base augmented with an outer metal plate over much of theinterior region of the large panel surface of each portion. The metalplate extends to the edges of the panel at the connector ends of eachportion and is attached to both connectors. In addition, smaller metalstrips, or ears, on both sides at the finger-grip end (opposite to thehost connector) extend from the plate to the edges of the panel andcontinue onto the sides. The frame kit is assembled and the side stripsare sonically welded together on both sides of the casings. The weldedstrips and plates form a single continuous metal band around the top andbottom frames that permanently physically retains the assembled kit.

[0057] I/O Interconnect Options

[0058] I/O devices may be interconnected with the expansion card viathree different embodiments. First, a PC-Card industry-standardHonda-style 15-pin connector may be used with a mating detachable cable.Detachable cables are preferred for light-duty applications where acontinuous I/O device connection is neither needed nor desired. Second,a fully integrated fixed cable, having a molded strain relief may beused. Such a fixed cable maintains solid contact in high vibrationenvironments, is protected against lateral stress, and seals out dust.Fixed cables are preferred for dedicated industrial or fieldapplications. Third, at least a portion of the I/O device may be abuttedand attached (often via a snap-in-place mechanism) directly to theexpansion card, obviating the need for either a detachable or fixedcable. Cableless snap-on I/O devices are preferred for small mostlyself-contained I/O devices that permit a compact PDA, expansion-card,I/O-device combination that handles physically as a single piece ofequipment. In the instant invention, such snap-on I/O devices must makeallowance for the removable memory.

[0059] PDA having Application Specific Card with Removable Media

[0060]FIG. 7 illustrates a PDA 200 equipped with a removable expansioncard 100 having both I/O interconnect 140 and removable memory 120 inaccordance with the present invention. The application specificcircuitry of the expansion card may be used in conjunction withapplication specific software running on the PDA. This permits theapplication specific circuitry of the expansion card to make use of theoutput (e.g., display, sound) and input (e.g., tablet, buttons, any I/Oports) capabilities of the PDA for user interface functions associatedwith the specific application. In particular the PDA'sdisplay/input-tablet provides for virtual controls and visual indicatorsfor the application. FIG. 8 illustrates some of the various types of I/Ofor which the PDA and removable expansion card of FIG. 7 may beequipped. Application-specific functions may include special-functionmixed-signal electronics, special-function I/O, special-functiondata-pumps, and special-function accelerators.

APPLICATION SPECIFIC EMBODIMENTS

[0061] Generic Removable Media Applications

[0062] The present invention enables general-purpose portable hosts toperform application-specific functions requiring dedicated ROM. A firstlarge ROM-based application category is that of prerecorded media, suchas music, audio, video, and text (for books, newspapers, and otherpublications). A second large ROM-based application category iscustomization for programmable devices, such as games, languagetranslators, and other devices having “personality” modules.

[0063] The present invention also enables general-purpose portable hoststo perform application-specific functions requiring non-volatileread/write memory for data-capture, data-logging, data-checkpoints orbackups, transaction logging, and data-transport.

[0064] In the illustrated embodiments the non-volatile read/write memoryis flash memory in accordance with the standard MultiMediaCard. Suchremovable flash-memory-based application-specific functions haveparticular utility to medical and other data acquisition, securecommerce, financial and personal productivity devices making use ofunique removable memories for each of multiple individuals, projects, oraccounts.

[0065] The removable flash-based memory is also well suited where“sneaker-net” is a viable data transport. Provided manual/userintervention is acceptable, and depending on the speed of data link I/Oincorporated into the expansion card, the physical transport of aremovable memory device between a PDA-based expansion card and anexternal system may provide the best solution to fast local transport oflarge data-sets. For similar reasons, the use of removable memorydevices may provide the best solution to rapidly reconfiguring anapplication-specific expansion card to initiate a large program or use alarge data sets. The use of labeled, color-coded, or otherwisedistinctive, removable memory devices also may provide the best solutionfor ease of use for users needing to select a particular program or dataset from many for reconfiguring an application specific expansion card.

SPECIFIC APPLICATION EXAMPLES

[0066] Media Player Application

[0067] The present invention permits a general purpose PDA to becustomized (specially adapted) for use as a portable/wearable mediaplayer, at the highest-level of functionality not unlike a portableCompact Disk player. Such a player uses the removable memory to storeand playback digitally encoded media such as music, audio, or video. Ina preferred embodiment the player makes use of the MPEG Layer 3 standardfor digital audio encoding, generally known as MP3. Another embodimentmakes use of the Microsoft Digital Audio standard. Other aspects of apreferred embodiment include an integral AM/FM receiver, a connector fora headset with an integral antenna for the receiver, and an auto-starton insert feature that initiates the media playback upon insertion ofthe removable memory. The PDA's display/input-tablet provides thevirtual controls and visual indicators for the media player.

[0068] Module For Subscriber Services

[0069] In accordance with the present invention, an expansion cardhaving I/O and removable memory is inserted into a computer host. TheI/O is coupled to a receiver capable of receiving a large number ofbroadcast messages and services. The removable memory containssubscriber services information for each individual user. The expansioncard uses the subscriber services information to filter out messages andservices not applicable to the present status of the subscriber. ThePDA's display/input-tablet provides the virtual controls and visualindicators for the display and access of captured messages and services.

[0070] Bar-Code Scanning Application (a Backup storage Example)

[0071] In accordance with the present invention, an expansion cardhaving I/O and removable memory is inserted into a computer host, abar-coding peripheral is connected to the I/O portion of the card, and aremovable memory card is inserted into the memory slot of the card.After each scan the scanned information is transferred through the I/Oconnection to the host computer for processing. Additionally, a backupcopy of the scanned information is stored on the removable memory.Should the computer host fail or should the operator need to verifyscans, the backup can be interrogated with the same or a different host.

[0072] Personal Environmental and Medical Monitoring Devices

[0073] The present invention permits a general purpose PDA to becustomized as a portable/wearable personal environmental monitor.Equipped with the appropriate sensors and application-specific circuitryfor sensor signal processing, such a device performs time-stamped datalogging of environmental attributes such as ionizing radiation,temperature, and humidity. Similarly, a portable/wearable personalmedial monitor data logs health-related attributes such as pulse,temperature, respiration, and blood pressure. The PDA'sdisplay/input-tablet provides the virtual controls and visual indicatorsfor the monitoring devices.

[0074] Automotive and Industrial Diagnostic Monitoring and Control

[0075] The combined I/O interconnect and removable memory of the presentinvention also permits a general purpose PDA to be customized (speciallyadapted) for use as a data logging diagnostic monitor or time-basedcontrol device. It is known that the diagnostic connectors of certainvehicles can be adapted to interface with PDAs for real-time monitoringof critical vehicle subsystems. The present invention permits suchdiagnostic monitoring data to be communicated via the I/O interconnectand logged to the removable memory. Such a tool facilitates trackingsubsystem performance over extended periods of time, and permitsreal-time and deferred graphics of time-varying system performanceattributes. The PDA's display/input-tablet provides the virtual controlsand visual indicators for the diagnostic monitor.

[0076] Conclusion

[0077] Although the present invention has been described usingparticular illustrative embodiments, it will be understood that manyvariations in construction, arrangement and use are possible within thescope of the invention. For example the number of I/O interconnects,removable memories, contact fingers, number and type ofapplication-specific circuits, and the size, speed, and type oftechnology used may generally be varied in each component of theinvention. The invention is not limited to the standard CompactFlashform factor, but other closed-case removable expansion card form factorsare equally applicable. Nor is the invention limited to use of thestandard MultiMediaCard, as other types of removable memory or media mayalso be employed. Functionally equivalent techniques known to thoseskilled in the art may be employed instead of those illustrated toimplement various components. The present invention is thus to beconstrued as including all possible modification and variationsencompassed within the scope of the appended claims.

We claim:
 1. A removable expansion card for a portable host, comprising:an expansion card frame and PCB, a host-interconnect for coupling withthe host, an I/O interconnect for coupling with an external I/O device,I/O adapter circuitry for the I/O device, a slot for a removable memory,and removable memory adapter circuitry for the removable memory.
 2. Thecard of claim 1, wherein the card is a CompactFlash card.
 3. The card ofclaim 1, wherein the removable memory slot is compatible with aMultiMediaCard, and the removable memory adapter circuitry isMultiMediaCard adapter circuitry.
 4. The card of claim 1, wherein theI/O adapter circuitry is a serial I/O adapter and the I/O-interconnectincludes a cable having a standard serial connector.
 5. The card ofclaim 1, wherein the I/O adapter circuitry is a local area networkadapter and the I/O-interconnect includes a cable having a standardlocal area network connector.
 6. The card of claim 1, wherein the I/Oadapter circuitry is a parallel adapter and the I/O-interconnectincludes a cable having a standard parallel connector.
 7. The card ofclaim 1, wherein the I/O-interconnect is a Honda-style 15-pin connectorintegral to the card.
 8. The card of claim 1, wherein the card isdesigned to abut and fasten with at least part of the I/O device suchthat the I/O-interconnect for coupling with the I/O device is cableless.9. A removable expansion card for a portable host, comprising: anexpansion card frame and PCB, the PCB having decoder and reconstructioncircuitry for digitally encoded media, the decoder and reconstructioncircuitry having a first low-level analog signal output, the card havinga slot for a removable memory holding at least one digitally encodedinstance of at least one media type, the card including removable memoryadapter circuitry for interfacing with the removable memory, and thecard having analog electronics for providing a media output.
 10. Thecard of claim 9, wherein the card is a CompactFlash card.
 11. The cardof claim 9, wherein the removable memory slot is compatible with aMultiMediaCard and the removable memory adapter circuitry is aMultiMediaCard adapter circuitry.
 12. The card of claim 9, wherein thedigitally encoded media is encoded in accordance with the MP3 standard.13. The card of claim 9, wherein the digitally encoded media is encodedin accordance with the Microsoft Digital Audio standard.
 14. The card ofclaim 9, wherein the playback of the digitally encoded media isinitiated automatically upon insertion of the removable memory.
 15. Thecard of claim 9, wherein the card further includes: a radio-frequencyreceiver providing a second low-level analog signal output, a low-levelselector coupled to the first and second low-level analog signal outputsand providing an input to the analog electronics, and antenna couplingelectronics associated with the media output for use with a headsetdesigned to function as an antenna for the radio-frequency receiver. 16.The card of claim 9, wherein the card further includes a local areanetwork adapter.
 17. The card of claim 16, wherein the local areanetwork adapter is an Ethernet adapter.
 18. A method of digitallyencoded media playback, comprising: providing a PDA, providing anexpansion card for the PDA having playback circuitry for the digitallyencoded media, providing a slot in the expansion card for receiving aremovable memory, providing the removable memory, providing I/O couplingfrom the PDA to an external system, transferring the digitally encodedmedia from the external system to the PDA, transferring the digitallyencoded media from the PDA to the expansion card, storing the digitallyencoded media from the expansion card to the removable memory, afterstoring later reading the digitally encoded media from the removablememory, decoding the digitally encoded media and producing areconstructed media, coupling the reconstructed media to a media outputof the expansion card, providing application software for the PDA toprovide user interface functions using the display and input devices ofthe PDA for controlling the storing and playback of the digitallyencoded media.
 19. The method of claim 18, wherein the I/O couplingincludes a local area network connection and the external systemincludes an Internet web-site.
 20. The method of claim 18, wherein thedigitally encoded media is encoded in accordance with the MP3 standard.21. The method of claim 18, wherein the digitally encoded media isencoded in accordance with the Microsoft Digital Audio standard.
 22. Themethod of claim 18, wherein the playback of the digitally encoded mediais initiated automatically upon insertion of the removable memory.
 23. Aremovable expansion card for a portable host, comprising: an expansioncard frame and PCB, the card having serial I/O circuitry, the cardhaving a serial I/O interconnect compatible with the serial I/O of adigital telephone, the card having a slot for a removable memory holdingdata including address book records, the serial I/O interconnectproviding communication between the telephone and the card of the dataassociated with the removable memory, the card including removablememory adapter circuitry for interfacing with the removable memory. 24.A removable expansion card for a portable host, comprising: an expansioncard frame and PCB, the card having serial I/O circuitry, the cardhaving a serial I/O interconnect compatible with the serial I/O of adigital telephone, the card having a slot for a removable memory forholding data including digitally encoded telephone communications, theserial I/O interconnect providing communication between the telephoneand the card of the data associated with the removable memory, the cardincluding removable memory adapter circuitry for interfacing with theremovable memory.
 25. A removable expansion card for a portable host,comprising: an expansion card frame and PCB, the card having serial I/Ocircuitry, the card having a serial I/O interconnect compatible with theserial I/O of a digital telephone, the card having a slot for aremovable memory holding data including address book records anddigitally encoded telephone communications, the serial I/O interconnectproviding communication between the telephone and the card of the dataassociated with the removable memory, the card including removablememory adapter circuitry for interfacing with the removable memory. 26.A removable expansion card for a portable host, comprising: an expansioncard frame and PCB, the card having serial I/O circuitry, the cardhaving a serial I/O interconnect compatible with the serial I/O of a GPSreceiver, the card having a slot for a removable memory holding dataincluding map information, the serial I/O interconnect providingcommunication between the GPS receiver and the card of the dataassociated with the removable memory, the card including removablememory adapter circuitry for interfacing with the removable memory. 27.The card of claim 26 wherein the map information includes informationabout city streets.
 28. A removable expansion card for a portable host,comprising: an expansion card frame and PCB, a host interface,interconnect for an external I/O device, and I/O adapter for the I/Odevice, an internal connector for a removable memory, a slot in theexpansion card frame for the removable memory, controller logic for theremovable memory.
 29. The card of claim 28, further includingapplication-specific circuitry, and wherein the removable memory is aprivate memory for the application-specific circuitry, the management ofthe removable memory being an ancillary function to the primary functionof the specific application.
 30. The card of claim 29, wherein the I/Oadapter is coupled to the application-specific circuitry and is notcoupled to the PDA.
 31. A method of customizing a PDA for anapplication-specific function, the method comprising: providing a PDA,providing an expansion card for the PDA having application-specificcircuitry, providing a slot in the expansion card for receiving aremovable memory, providing removable memory adapter circuitry withinthe expansion card for the removable memory, providing the removablememory to the expansion card, reading and writing the removable memoryby the removable memory adapter circuitry in accordance with theapplication-specific function, providing application software for thePDA to provide user interface functions using the display and inputdevices of the PDA for controlling the application-specific function.32. The method of claim 31, further including: providing an I/O adapterwithin the card, providing I/O coupling from the I/O adapter to anexternal system, and transferring data between the external system andthe I/O adapter.
 33. The method of claim 32, further includingtransferring the data between the I/O adapter and the PDA.
 34. Themethod of claim 32, wherein the I/O adapter is a network adapter, andwherein the I/O coupling includes a network connection, and the externalsystem includes a web-site.
 35. The method of claim 33, wherein at leastone of the PDA and the card have at least a first and a second powermode and a message received over the network by the card selectivelyresults in a transition from the first power mode to the second powermode.
 36. The method of claim 32, wherein the I/O adapter is acommunications receiver, and wherein the I/o coupling includes acommunications link, and the external system includes a communicationstransmitter.
 37. The method of claim 35, wherein at least one of the PDAand the card have at least a first and a second power mode and a messagereceived over the communications link by the card selectively results ina transition from the first power mode to the second power mode.
 38. Themethod of claim 32, wherein at least part of the external system isabutted and fastened to the expansion card such that the I/O coupling iscableless.